Screw-holding screw driver



Sept. 18, 1956 J, N 2,763,304

SCREW-HOLDING SCREW DRIVER Filed Aug. 31, 1953 2 Sheets-Sheet 1 Q /0 Z9 I i g :i: :1:

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JAMES M. NEIL ATTGQNEV' Sept. 18, 1956 J. M. NEIL SCREW-HOLDING SCREW DRIVER 2 Sheets-Sheet 2 57 FIGURE Filed Aug. 51, 1953 F/GURE 7 INVENTOR. JAMES M. NEIL ATTORNEY United States PatentO SCREW-HOLDING SCREW DRIVER James 'M. Neil, Oakland, Calif.

Application August 3.1, 1953, Serial No. 377,420

6 Claims. (Cl. 145-50) This invention relates to screwdrivers which are adapted to hold the screw during insertion and removal, and particularly screws of the Phillips" type.

One of the objects of the invention is to provide a screwdriver of the Phillips type with a manually-controlled automatically-operable means for holding a screw of the Phillips type.

Other objects will be evident in the disclosure which follows.

For a detailed disclosure of a screwdriver of the type in which the invention is embodied, reference is to be had to the patent to Henry F. Phillips, 2,046,837. While a screwdriver constructed in accordance with the teachings of this patent does have some holding power over the screw through the weding action of its vanes in the cruciform kerf of the screw, the screw is easily dislodged and may be accidentally lost from the screwdriver.

Some thought has been given to overcoming this disadvantage as evidenced by the patent to L. E. Bier, 2,625,971, which discloses an attachment which supplants the regular Phillips bit.

In accordance with my invention the gripping means is built into a Phillips screwdriver and cooperates therewith to increase its holding power to the point where for all practical purposes the screw is locked on the screwdriver. Tests with a screwdriver constructed in accordance with my invention reveal that it is physically impossible for a person to pull the screw loose from the screwdriver, yet it may be released by a touch of the finger on the control.

A detailed description will now be given by reference to the drawings wherein:

Figure 1 is an elevation of my screwdriver with screw attached.

Figure 2 is an enlarged partial section of the gripping means actuator and control.

Figure 3 is an enlarged elevation of the bit and gripping means.

Figure 4 is a horizontal section taken as indicated by line 44 in Figure 3.

Figures 5 to 7 show a preferred embodiment of my invention.

Figure 5 is a side elevation of the bit and gripping means.

Figure 6 is an end elevation thereof.

Figure 7 shows how the screw is gripped, the portion in section being a section on line 77 in Figure 5.

As shown in Figure 1 the screwdriver is provided with a handle 10 and a bit 11 having flutes 12. A screw 13 is held by the screwdriver and may be released by touching the control button 14.

As shown in Figure 2 the handle 10 is secured to a cylinder 20 by a pin 21. The upper end of the bit 11, which is a sleeve, fits in the lower end of the cylinder 20 and is adapted to be secured therein by a set screw 22 so that the handle 10 and bit 11 are joined for movement an a unit. A shaft 23 is rotatably mounted in the 2,763,304 Patented Sept. 18, 1956 ICC '2 sleeve 11 and the upper end 24 of the shaft, which is reduced in diameter, is rotatable in a bore 25 in the cylinder 20.

A collar 26 abuts the shoulder on the shaft 23 and is .secured to said shaft by a pin 27 which is integral with the before-mentioned button 14. The pin 27 passes through a slot 28 in the cylinder 20 which permits limited rotation of the shaft 23 in the cylinder and the sleeve. The shaft 23 is urged in a clockwise direction as viewed from above by a torsion spring 29 having its upper end anchored in a hole in the cylinder 20 and its lower en in a hole in the collar '26.

Rigidly secured to the lower end of the shaft 23 (Figure 3) is the gripping element 30 which is rotatable with respect to the bit 11 as shown in Figure 4. Under the action of the torsion spring 29 and the limitation of the slot '28 the element 30 normally occupies the position shown in Figure 4. When the operator presses his thumb against the button 14 the element 30 moves to the position shown in Figure 3.

It is to be noted in Figure 3 that the bit is constructed in two parts. The bit 11 is truncated at 31 and the element 30 forms an elongation thereof. Also the flutes 12 of the bit 11 are extended at 32 through the element 30 and the vanes 33 of the bit 11 are extended at 34 in the element 30 so that in the Figure 3 position the vanes 33 and 34 will fit in the kerf of the screw in exactly the same manner as the vanes of a standard Phillips bit.

Thus in order to attach the screw the operator grasps the handle 10 in one hand, presses the button 14 with the thumb of that hand, presses the screw onto the bit with his other hand, and then releases the button, whereupon the spring applies its pressure to rotate the shaft 23 and its element 30. This results, in effect, in expansion of the vanes of the bit, the vanes 34 being urged out of alignment with the vanes 33. And the sides 35 of the vanes 34 in the element are pressed against the adjacent walls of the kerf in the screw, thereby gripping the screw.

To increase the gripping power of the element still further I change the contact between the element and the screw from surface contact to line contact as will now be explained by reference to Figure 5, 6 and 7.

Figure 5 shows the truncated bit 50, which is similar to the previously described bit 11, and shaft 51, which is similar to shaft 23. Gripping element 52 is a modified form of element 30.

In Figure 6 the vanes of the bit appear at 53 and the flutes at 54. Element 52 is shown in full lines in its normal position and in broken lines in its retracted position which it occupies when the operator presses the control button.

t is to be particularly noted here that the flutes 55 in the element 52 are not prolongations of the flutes 54 in the bit. The flutes 55 are so disposed as to relieve contact between the wall of each vane 58 and the screw by having said wall recede at 59, so that only the edge 60 can engage the wall of the kerf in the screw.

This is best shown in Figure 7 where it is assumed that the operator has attached the screw 70 and released the control button so that the spring has rotated the gripping element. Notice that the leading edge 60 of the vane 58 has dug into the wall 71 of the kerf, thus acting as a barb and positively preventing loss of the screw "it; from the bit 50.

Having disclosed my invention, I claim:

1. A screwdriver having a bit, said bit comprising two parts, each of said parts being cruciform in cross-section, and means for moving said parts relative to each other to grip the screw.

2. A screwdriver having a bit for insertion in the kerf of a screw, said bit having two axially displaced parts, both said parts being cruciform in cross-section one of said parts being adapted to engage the top portion of the kerf, and the other of said parts being adapted to engage the bottom portion of the kerf, and means to rotate said two parts relative to each other to hold the screw.

3. A screwdriver having a handle, a bit connected to said handle and adapted to engage the upper portion of the kerf of a screw, a gripping element axially displaced from said bit and rotatable relative to said bit to engage the lower portion of the kerf of the screw, said bit and said element being cruciform in cross-section, and means for rotating said element.

4. A screwdriver having a handle, a bit connected to said handle and adapted to engage the upper portion of the kerf of a screw, a gripping element axially displaced from said bit and rotatable relative to said bit to engage the lower portion of the kerf of the screw by line contact with the walls of the kerf, said bit and said element being cruciform in cross-section, and a spring for rotating said element.

5. A screwdriver having a shank, one end of said shank having a plurality of flutes extending longitudinally of said shank, a supplementary part on said end of said shank mounted for coaxial movement relative thereto, said supplementary part having extensions of said flutes therein, said end of said shank and said supplementary part comprising an expansible bit.

6. A screwdriver having a shank, one end of said shank being fluted longitudinally to provide a plurality of vanes, a supplementary part mounted on said end of said shank for coaxial movement relative thereto, said supplementary part having vanes which are extensions of said vanes in said shank, said vanes in said supplementary part being undercut to provide sharp edges for engaging the walls of the kerf in a screw, and spring means for rotating said supplernentarypart relative to said shank.

References Cited in the file of this patent UNITED STATES PATENTS 785,162 Freytag Mar. 21, 1905 1,063,304 Titus June 13, 1913 1,344,542 Lane June 22, 1920 1,781,470 Mueller Nov. 11, 1930 2,046,837 Phillips July 7, 1936 2,161,095 Schaifer June 6, 1939 2,329,398 Duffy Sept. 14, 1943 2,451,696 Sopcak Oct. 19, 1948 2,522,164 Clough Sept. 12, 1950 2,566,683 Thompson Sept. 4, 1951 

